While deep decarbonization scenarios depend on reducing carbon dioxide emissions per unit of economic activity by 4% to 10% per year, economies only managed to reduce that carbon intensity by 0.9% per year between 1990 and 2005.
That means research is needed to better understand the factors that lead to reduced energy intensity, and “scenarios calling for a step-change acceleration in energy intensity rates should be treated with caution” until the research is complete, Jesse Jenkins and Armond Cohen report on The Energy Collective.
“Energy intensity improvements feature prominently in almost all published scenarios proposing strategies to decarbonize the global economy and drive down emissions,” they write. But “the rates envisioned in these scenarios stand in marked contrast with the historical rate of progress in energy intensity.”
The article lists sectoral shifts in the economy, substitution of capital or labour for energy, higher energy conversion efficiency, and improvements in end-use efficiency as factors that could contribute to rapid improvements in energy intensity. But “only a few of these mechanisms can be affected by energy and climate policy levers.”
And to date, “only a fraction of the overall final energy intensity improvement rates seen historically have anything to do with the wide range of end-use energy efficiency or climate policies pursued by a variety of nations over the past four decades.”